Instrumentation

The AUV 'Sirius' ready for survey work at Scott Reef, Western Australia (Photo: Australian Centre for Field Robotics).

The Autonomous Underwater Vehicle facility currently owns and operates the ocean going AUV called ‘Sirius’. Managed by the University of Sydney’s Australian Centre for Field Robotics (ACFR) this vehicle is a modified version of a mid-size robotic vehicle called Seabed built at the Woods Hole Oceanographic Institution. Sirius is 2.0m long by 1.5m high by 1.5m wide and weighs approximately 200kg. It has a maximum speed of 1m/s and can descend to depths of 700m. Sirius is specifically designed for undertaking high resolution benthic optical and acoustic imaging work and is equipped with a full suite of oceanographic instruments. These include a high resolution stereo camera pair and strobes, a 330 kHz multibeam sonar, depth and conductivity/temperature sensors, a 1200 kHz Doppler Velocity Log (DVL) including a compass with integrated roll and pitch sensors and a flurometer to measure coloured dissolved organic matter (CDOM) and chlorophyll-a and backscatter. Data is time-stamped and logged on the vehicles on-board computer. A variety of navigational sensors including GPS, Ultra Short Baseline Acoustic Positioning System (USBL) and forward looking obstacle avoidance sonar, enable precise tracking of the vehicle. This permits survey data collected by Sirius to be geo-referenced at high precision. It is anticipated that future planned upgrades of Sirius’ on-board data storage and battery system will allow for faster turn-around between dives, increasing the number of dives that can be achieved per day and therefore maximising the efficiency of data collection.